For its advocates, it is a miraculous elixir that has replaced the morning coffee as their first drink of the day; for most other people, it is bodily waste that should strictly confined to the toilet bowl. But is drinking one’s own urine really as good for you as its fans believe?

Last week, British hiker Paul Beck was stranded in the Spanish mountains for six days – and survived by drinking his own urine. The 33-year-old slipped and dislocated his hip while walking. As he waited for rescuers to find him, he tried to exist on powdered chocolate and raw oats, but eventually resorted to urinating into a cup and drinking a few drops a day. He said: “It was pretty awful but in all I did it around five times to keep myself hydrated.”

And last year, yachtsmen Mark Smith and Steven Freeman spent 11 days stranded in the South China Sea after their boat capsized and put their survival down to urine.

But apart from possibly helping to keep one alive in extreme circumstances, is drinking urine really good for your health?

Auto-urine therapy, or urotherapy as it is sometimes known, dates back to several ancient cultures and even, arguably, the Bible. Egyptian medical texts and Chinese and Indian documents mention the benefits of drinking one’s urine, while the Aztecs used it to disinfect wounds.

Contrary to popular perception, urine is not a by-product of the body’s waste disposal system but of blood filtration. Nutrient-filled blood passes through the liver, where toxins are removed and excreted as solid waste. The purified blood then goes through another filtering process via the kidneys, where components for which the body has no immediate use are collected in a sterile, watery solution. For that reason, it is highly sterile, consisting of 95 per cent water and five per cent nutrients, including vitamins, minerals, proteins, antibodies and other beneficial ingredients.

Advocates of auto-urine therapy believe that this combination can help cure everything from the common cold to cancer, boosting energy levels and sexual performance along the way. While the practice has always been popular in China, India and South-east Asia, a small but growing band of Western fans are also downing a daily dose. Books with titles such as The Golden Fountain all extol the virtues of urine.

One of the prime movers in the movement, Martha Christy (author of Your Own Perfect Medicine) says that the first toilet visit of the day is the most beneficial. She recommends a regime beginning with five drops of “fresh morning urine” under the tongue before gradually increasing the dosage to as much as a cupful, morning and night. Urine can also be used as eye and ear drops, for gargling with or in the bath.

Ms Christy, who claims that drinking urine cured her of a host of medical problems, says that doctors have deliberately not highlighted the benefits of auto-urine therapy because there are no profits in it for them.

But there is little firm proof for the claims made about the therapy and medical experts have remained unconvinced. Dr Michael Stroud, an expert in nutrition at Southampton University and who has been in many extreme situations during his record-breaking expeditions with explorer Sir Ranulph Fiennes, says that people who believe that their urine can cure them of Aids and improve their complexions are “daft as brushes”.